HD64F2149 Datasheet, PDF (696/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

22.4.3 Flash Memory Operating Modes
Mode Transitions: When the mode pins are set in the reset state and a reset-start is executed, the
MCU enters one of the operating modes shown in figure 22.3. In user mode, flash memory can be
read but not programmed or erased.
Flash memory can be programmed and erased in boot mode, user program mode, and programmer
mode.
MD1 = 1
Reset state
User mode with
on-chip ROM
enabled
SWE = 0
SWE = 1
RES = 0
RES = 0
User
program mode
RES = 0
*2
*1 _{RES = 0}
Programmer
mode
On-board programming mode
Boot mode
Notes: Only make a transition between user mode and user program mode when the CPU is
not accessing the flash memory.
1. MD0 = MD1 = 0, P92 = P91 = P90 = 1
2. MD0 = MD1 = 0, P92 = 0, P91 = P90 = 1
Figure 22.3 Flash Memory Mode Transitions
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